Add support for guessing ar/ranlib signatures

1 files changed, 154 insertions, 0 deletions

diff --git a/build2/bin/guess.cxx b/build2/bin/guess.cxx
new file mode 100644
index 0000000..1cdb40d
--- /dev/null
+++ b/build2/bin/guess.cxx
@@ -0,0 +1,154 @@
+// file      : build2/bin/guess.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <build2/bin/guess>
+
+#include <build2/diagnostics>
+
+using namespace std;
+
+namespace build2
+{
+  namespace bin
+  {
+    bin_info
+    guess (const path& ar, const path& ranlib)
+    {
+      tracer trace ("bin::guess");
+
+      bin_info r;
+      string& as (r.ar_signature);
+
+      // Binutils, LLVM, and FreeBSD ar/ranlib all recognize the --version
+      // option, so start with that.
+      //
+      {
+        auto f = [] (string& l) -> string
+        {
+          // Binutils ar --version output has a line that starts with
+          // "GNU ar ".
+          //
+          if (l.compare (0, 7, "GNU ar ") == 0)
+            return move (l);
+
+          // LLVM ar --version output has a line that starts with
+          // "LLVM version ".
+          //
+          if (l.compare (0, 13, "LLVM version ") == 0)
+            return move (l);
+
+          // FreeBSD ar --verison output starts with "BSD ar ".
+          //
+          if (l.compare (0, 7, "BSD ar ") == 0)
+            return move (l);
+
+          return string ();
+        };
+
+        // Suppress all the errors because we may be trying an unsupported
+        // option.
+        //
+        sha256 cs;
+        as = run<string> (ar, "--version", f, false, false, &cs);
+
+        if (!as.empty ())
+          r.ar_checksum = cs.string ();
+      }
+
+      // On Mac OS X (and probably also older BSDs) ar/ranlib doesn't have an
+      // option to display version or help. If we run it without any arguments
+      // it dumps usage and exist with an error status. So we will have to use
+      // that.
+      //
+      if (as.empty ())
+      {
+        auto f = [] (string& l) -> string
+        {
+          return l.find (" ar ") == string::npos ? string () : move (l);
+        };
+
+        // Redirect STDERR to STDOUT and ignore exit status.
+        //
+        sha256 cs;
+        as = run<string> (ar, f, false, true, &cs);
+
+        if (!as.empty ())
+        {
+          l4 ([&]{trace << "generic ar signature '" << as << "'";});
+
+          r.ar_signature = "Generic ar";
+          r.ar_checksum = cs.string ();
+        }
+      }
+
+      if (as.empty ())
+        fail << "unable to guess " << ar << " signature";
+
+      // Now repeat pretty much the same steps for ranlib if requested.
+      //
+      if (ranlib.empty ())
+        return r;
+
+      string& rs (r.ranlib_signature);
+
+      // Binutils, LLVM, and FreeBSD.
+      //
+      {
+        auto f = [] (string& l) -> string
+        {
+          // "GNU ranlib ".
+          //
+          if (l.compare (0, 11, "GNU ranlib ") == 0)
+            return move (l);
+
+          // "LLVM version ".
+          //
+          if (l.compare (0, 13, "LLVM version ") == 0)
+            return move (l);
+
+          // "ranlib " (note: not "BSD ranlib " for some reason).
+          //
+          if (l.compare (0, 7, "ranlib ") == 0)
+            return move (l);
+
+          return string ();
+        };
+
+        sha256 cs;
+        rs = run<string> (ranlib, "--version", f, false, false, &cs);
+
+        if (!rs.empty ())
+          r.ranlib_checksum = cs.string ();
+      }
+
+      // Mac OS X (and probably also older BSDs).
+      //
+      if (rs.empty ())
+      {
+        auto f = [] (string& l) -> string
+        {
+          return l.find ("ranlib") == string::npos ? string () : move (l);
+        };
+
+        // Redirect STDERR to STDOUT and ignore exit status.
+        //
+        sha256 cs;
+        rs = run<string> (ranlib, f, false, true, &cs);
+
+        if (!rs.empty ())
+        {
+          l4 ([&]{trace << "generic ranlib signature '" << rs << "'";});
+
+          r.ranlib_signature = "Generic ranlib";
+          r.ranlib_checksum = cs.string ();
+        }
+      }
+
+      if (rs.empty ())
+        fail << "unable to guess " << ranlib << " signature";
+
+      return r;
+    }
+  }
+}